Ashkenazi Jewish and Other White APC I1307K Carriers Are at Higher Risk for Multiple Cancers.

Purpose: APC I1307K has a higher prevalence among Ashkenazi Jews (AJ), and a two-fold increased risk for colorectal cancer (CRC) compared to non-Jewish populations. We assessed CRC and extracolonic malignancies among I1307K carriers from AJ and non-AJ whites (NAW). Methods: We compared the rate of I1307K in cancer patients who underwent germline genetic testing via a multi-gene panel with healthy subjects retrieved from the gnomAD database. Cases undergoing testing were not selected and testing was undertaken through a commercial laboratory. Results: Overall, 586/7624 (7.6%) AJ with cancer carried I1307K compared to 342/4918 (6.9%) in the AJ control group (p = NS). In the NAW, 318/141,673 (0.2%) cancer patients and 73/58,918 (0.1%) controls carried the variant [OR = 1.8, (95% CI 1.41−2.35), p < 0.001]. I1307K in NAW was associated with an increased risk of CRC [OR = 1.95, (95% CI 1.39−2.73), p < 0.01], melanoma [OR = 2.54, (95% CI 1.57−3.98)], breast [females, OR = 1.73, (95% CI 1.18−2.65), p < 0.01], and prostate cancer [males, OR = 2.42, (95% CI 1.45−3.94), p < 0.01]. Among AJ, the variant increased the risk for CRC [OR = 1.67, (95% CI 1.36−2.05), p < 0.001] and renal cancer [OR = 1.64, (95% CI 1.04−2.47)]. AJ men had a higher risk for any cancer [OR = 1.32, (95% CI 1.05−1.66), p < 0.05] and melanoma [OR = 2.04, (95% CI 1.24−3.22); p < 0.05]. Conclusions: This is the most extensive study to date conducted on I1307K carriers, although it is amenable to selection bias. NAW carrying I1307K had a higher risk of any cancer and several specific cancer types, whereas AJ carrying the variant had a risk for only a few select cancers. Our data add to the research base on I1307 carriers concerning future risk management.

Homozygous Germline APC p.I1307K Variants: A Case Series.

Approximately 10% of all colorectal cancer is estimated to be due to an inherited predisposition. Identification of a germline pathogenic variant can aid in treatment, screening, and surveillance and help stratify familial cancer risks based on gene-specific cancer associations. The APC gene contributes to a small percentage of hereditary colon cancer, with most pathogenic APC variants causing familial adenomatous polyposis syndrome. However, one specific variant in APC called p.I1307K, found in approximately 10% of Ashkenazi Jewish individuals, is associated with a moderate risk for colon cancer, but not polyposis. Heterozygous carriers of one p.I1307K variant are well documented in the literature, and guidelines recommend earlier and more frequent colonoscopies. Conversely, reports of homozygous carriers of 2 p.I1307K variants are limited, and guidelines for medical management are lacking. This case series describes 4 homozygous p.I1307K patients of Ashkenazi Jewish ancestry identified in cancer genetics clinics. Case 1 is a 73-year-old pancreatic cancer patient with a family history of melanoma and colon cancer. Case 2 is a 62-year-old patient with a personal history of 4 adenomatous colorectal polyps and a family history of breast, pancreatic, colon, and prostate cancers. Case 3 is a 52-year-old patient with a personal history of early-onset breast cancer and uveal melanoma and a family history of breast, prostate, and stomach cancers. Case 4 is a 70-year-old patient with a personal history of gallbladder adenocarcinoma and a family history of breast cancer. These cases exhibit wide phenotypic variability and contribute to the limited reports of homozygous p.I1307K variant carriers.

The APC I1307K allele conveys a significant increased risk for cancer.

This study is the first attempt to evaluate the association between the APC I1307K variant and overall cancer risk. It is unique in both its large sample size and in the reliability of data in the control group. The findings described in this article have major implications in terms of identifying asymptomatic individuals who are at increased risk to harbor cancer and therefore targeted to be enrolled in specific early detection and prevention programs. The prevalence of the APC I1307K missense mutation among Ashkenazi Jews is ∼ 6%. Carriers are at an increased risk for colorectal neoplasia. In this study, we examined the association of this variant with non-colorectal cancers. Consecutive 13,013 healthy subjects who underwent screening at the Integrated Cancer Prevention Center between 2006 and 2014 were enrolled. This population was supplemented with 1,611 cancer patients from the same institution. Demographics, medical history, and pathological data were recorded. Mortality data were obtained from the Ministry of Health's registry. The prevalence of APC I1307K in cancer patients and healthy subjects was compared. The APC I1307K variant was detected in 189 (11.8%) cancer patients compared to 614 (4.7%) healthy subjects, reflecting an adjusted age and sex odds ratio (OR) of 2.53 (p < 0.0001). History of two or more cancer types was associated with a positive carrier prevalence (OR = 4.38 p < 0.0001). Males had significantly increased carrier prevalence in lung, urologic, pancreatic, and skin cancers. The carrier prevalence among females was significantly higher only in breast and skin cancers. Female carriers developed cancer at a significantly older age compared to non-carriers (average 62.7 years vs. 57.8, respectively, p = 0.027), had better survival rates (HR = 0.58, p = 0.022) and overall increased longevity (average age of death 78.8 vs. 70.4 years, respectively, p = 0.003). In conclusion, the APC I1307K variant is a reliable marker for overall cancer risk (OR 2.53). Further studies are needed to evaluate its use for specific cancer types-particularly in males. Female carriers have better prognosis and increased lifespan.

Association of APC I1307K and E1317Q polymorphisms with colorectal cancer among Egyptian subjects.

Colorectal cancer is a multifactorial disease that involves both environmental and genetic factors. The gene encoding adenomatous polyposis coli (APC) has been reported to be associated with colorectal cancer (CRC) risk in several ethnic populations. The aim of this work is to assess the association of the APC I1307K and E1317Q polymorphisms with CRC risk among Egyptian subjects. This study included 120 unrelated CRC Egyptian patients who were compared to 100 healthy controls from the same locality. For all subjects, DNA was genotyped for APC I1307K and E1317Q polymorphisms using the PCR-ARMS technique. The frequency of APC I1307K carrier (TA+AA genotypes) was noted to be significantly higher among cases with CRC compared to controls (18.3 vs. 9.0 %, OR 2.58, 95 % CI 1.09-6.09, p = 0.03). Also the frequency of the APC I1307K A allele was significantly higher among cases compared to controls (10.4 vs. 4.5 %, OR 2.47; 95 % CI 1.12-5.42, p = 0.03). On the contrast, the frequencies of APC E1317Q GC genotype and C allele showed no significant difference among CRC patients compared to controls (3.3 vs. 2.0 %, OR 1.69; 95 % CI 0.30-9.42, p = 0.69 and 2.1 vs. 1.0 %, OR 2.11; 95 % CI 0.40-10.97, p = 0.46, respectively). Cases of the APC I1307K and E1317Q carriers (TA+AA and GC) showed no significant difference compared to those with I1307K and E1317Q non-carriers (TT and GG) regarding their clinical and laboratory markers. APC I1307K variant was associated with an increased risk of CRC among Egyptian subjects.

The APC p.I1307K polymorphism is a significant risk factor for CRC in average risk Ashkenazi Jews.

BACKGROUND: The p.I1307K adenomatous polyposis coli (APC) gene variant, prevalent among Ashkenazi Jews, may increase the risk for colorectal neoplasia. We studied the clinical importance of screening for this polymorphism in 3305 Israelis undergoing colonoscopy. PATIENTS AND METHODS: Clinical data regarding potential risk factors for colorectal cancer (CRC) were collected from individuals undergoing colonoscopic examination at the Tel-Aviv medical center. The APC p.I1307K was detected using real-time PCR (polymerase chain reaction) from DNA extracted from peripheral mononuclear cells. RESULTS: The overall prevalence of the p.I1307K polymorphism was 8.0% (10.1% among Ashkenazi and 2.7% among Sephardic Jews, p<0.001). The overall adjusted odds ratio (OR) for colorectal neoplasia among carriers was 1.51 (95% confidence intervals (CI), 1.16-1.98). Among average risk Ashkenazi Jews, the adjusted OR was 1.75 (95% CI 1.26-2.45). A multiplicative interaction was identified between Ashkenazi ethnicity and APC p.I1307K carrier status (P(INTERACTION) = 0.055). The histopathological features of adenomas and carcinomas did not differ between carriers and non-carriers. CONCLUSIONS: The APC p.I1307K gene variant is an important risk factor for colorectal neoplasia in average risk Ashkenazi Jews. Carriers in this group should be considered for screening colonoscopy at the age of 40, to be repeated every 5 years, similar to recommendations in individuals with family history of colorectal cancer.